Besetting means fob aib borne



ay 9 M. F. BATES RESETTING MEANS FOR AIR BORNE GYROSCOPES Filed Nov. 2,1935 INVENTO lzgmmm 50155 v HIE AZRN Y.

.ntented M y 14, 1940 BESETTING MEANS FOR AIR BOBNE GYROSQOPES Mortimerr. Bates, Brooklyn, N. Y., assignor to Sperry Gyroscope Company, Inc,Brooklyn, N. Y., a corporation of New York I Application November2,1935, Serial No. 48,008

Claims.

This invention relates to gyroscopic directional and similar devices ofthe air borne type inwhich ordinary oil or ball bearings are replacedbybearings supported entirely by air films. Such gyro- 5 scopes are eitherused alone or operated in conjunction with a magnetic compass as agyromagnetic compass unit, as well understood in th art of aircraftnavigational instruments.

In directional gyroscopes which have three delo grees of freedom, it isoccasionally necessary to reset the same to bring the compass cardthereon into the desired course or into synchronism with the magneticcompass. For resetting the ordinary type of gyroscope, considerablemechanism to is required because the gyroscope must be locked about itshorizontal axis, but by my present invention I have devised an extremelysimple device for resetting air borne type directional gyroscopes.

Referring to the drawing, thsingle figure shows a. vertical section ofan air borne directional gyroscope with my resetting means appliedthereto.

The directional-gyroscope is shown as enclosed in a casing l having afront window to for reading the card i and from which air is exhaustedthrough a pipe coupling 2 by means of a pump (not shown). The gyroscopeis supported within said casing for freedom about its verticalaxis bymeans of upper and lower spherical air bearings 23 and t which supportand guide the vertical ring a about the vertical axis. The rotor bearingcasing e, in turn, is supported for oscillation about a horizontal axiswithin said vertical ring on spherical air bearings l and 8. Such airbearings are now well known in the art, as shown in the priorapplication of Leslie F. Carter, Serial No. 734,619, filed July 11,1934, and comprise large complementary, close fitting, curved, dry 4gmetallic surfaces between which air is caused to normally flow, wherebythe supported. member is floated in the supporting member. The rotor 9,in turn, is journalled in said casing for spinning about normallyhorizontal axis ill on any as suitable type of anti-friction bearing,preferably otherthan the air borne type.

- Air is shown as supplied to the instrument for lubricating or floatingthe bearings and spinning the rotor through a bottom screened openingit.

in;- The air passes upwardly through apertures t2, t2 and it within abearing block or cup is, shaped to closely fit the spherical button Iton the hottom of the vertical ring. A portion of said air said airpasses upwardly, however, through an opening I5 in line with the openingl3, whence it branches into channels l6 and I6 connecting with similarchannels I! and I1 and I8 and I8 which finally emerge through the topbutton l4 5 to supply air for lubricating or floating the same withinthe complementary shaped cup member I9. A portion of the air from eachsystem of channels is also led horizontally to float the rotor bearingcasing buttons 20 and 20' in the spherical 10 to the spinning nozzles 24for spinning the rotor.

As a locking means'for locking the gyroscope preliminary to resetting orshutting down, I have 20 shown a manually operated shut-off valve 25 Iadapted to close the outlet 2 at will. when said valve is closed, therotor bearing casing becomes immediately locked about its horizontal aswell as about its vertical axis because with the air re- 25 moved thelarge bearing surfaces, as they are not lubricated other than by air,are in frictional contact with each other. I have shown a common knob 26both for shutting off the air pump and for resetting the gyroscope. Asshown, said so knob is mounted on a shaft 21 both slidably and rotatablymounted in casing I. At the inner end of said shaft is a bevel gear 28adapted to be be brought into mesh with a bevel gear annulus re securedto the cup member IS, the latter beas ing rotatably mounted within theleasing I. There is also shown a U-shaped member 3i connecting the valve25 and the push rod 27. As shown, the extension of the rod 21 passesthrough a hole in the right hand upturned portion 532 of said member so.that said portion is non-slidably held between collars t3 and 33' onsaid shaft 2?. it will readily be apparent that by pushing the handlettin, the sourceof differential air-pressure, will be shut oil, therebyfrictionally locking the a gyroscope about both its vertical andhorizontal axes, and that by rotating the knob 26 the gyroscope may beset about its vertical axis to any desired position. The hearing it) ispreferably of the ball bearing type so that the rotor remains upspinning even though the gyroscope is locked about another axis.

Since the entire weight of the gyroscope is on the lower bearing, itwill ordinarily be found sufiicient to turn the lower bearing only. Asabove cal ring. With the ordinary type of resetting device, the frame isbrought to a position with the gyro spin axis perpendicular to thenormally vertical ring, but in case the vertical ring is inclined due tothe inclined position of the aircraft at that time, the spin axis of thegyro will also be brought to an inclined position by the former type ofsetting device. In my invention, however, the rotor bearing frame islocked in whatever position with respect to the vertical ring it may beat the time the air is out 011', so that when released again it willremain in that position.

From the foregoing description it will be readily apparent that I havedevised anextremely simple caging and resetting device. In the usualtype of directional gyroscope, a system of gears and levers has to beemployed to cage or look the gyroscope about its horizontal axis toprevent precession when resetting and it is also necessary to actuallyengage the vertical ring. In my system the caging function isaccomplished simply for shutting off the air supply, and the resettingsimply by turning the lower vertical bearing.

As many changes could be made in the above construction any manyapparently widely different embodiments of this invention could be madewithout departing from the scope thereof, it is intended that all mattercontained in the above description or shown in the accompanying drawingshall be interpreted as illustrative and not in a limiting sense. 4

Having described my invention, what I claim and desire to protect byLetters Patent is as follows:

1. In an air borne gyroscope having large complementary, dry bearingsurfaces between the supported and supporting, parts and means for leastone of said bearings while the air supply is ofl.

2. A resetting means for directional gyroscopes of the air borne typehaving a rotor bearing casing, a vertical ring and outer casing, largecomplementary dry bearing surfaces mounting said casing within said ringand mounting said ring within said outer casing for freedom abouthorizontal and vertical axes, means for supplying air flow between saidsurfaces to provide air flow bearings, means for shutting off the supplyof air to said bearings, and means for rotating the part of at least thelower vertical bearing in said casing, while the air supply is shut off.

8. A resetting means for directional gyroscopes of the air borne typehaving a rotor bearing casing, a vertical ring and outer casing, largecomplementary dry bearing surfaces mounting said casing within said ringand mounting said ring within said outer casing for freedom abouthorizontal and vertical axes, means for supplying air flow between saidsurfaces to provide air flow bearings, means for shutting off the airsupply to said bearings, means for rotating the lower-vertical bearingin said casing, and a common knob for operating both of said last namedmeans.

4. In a directional gyroscope, a rotor bearing casing, a rotatablymounted vertical ring, large complementary dry surfaces for supportingsaid casing for oscillation about a horizontal axis within said ring,means whereby air under pressure is supplied thereto for floating saidcasing about said axis, means for locking the casing about said axispreparatory to resetting by shutting off the air supply, means. fortemporarily cutting off the air supply, and means for resetting saidvertical ring and casing in azimuth while said casing is .so lockedabout said horizontal axis.

5. A directional gyroscope as claimed in claim 4, also having largecomplementary dry surface bearings supporting said ring for turningabout a vertical axis whereby the vertical ring is also looked inazimuth, and means for resetting the position of said vertical ring byutilizing the friction of the dry surfaces of the lower bearing of saidvertical ring while the rotor bearing casing of the gyroscope is solocked.

MOR'I'IMER F. BATES.

